<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>getElementsByTagName获取checkbox进行全选</title>
		<style type="text/css">
			#myTable{ width: 900px; margin: 0px auto; background-color: #008000;}
			#myTable td,#myTable th{ background-color: white;}
			#myDiv{width: 900px; margin: 0px auto; height: 30px; line-height: 30px; 
			text-align: center;}
		</style>
		<!-- <script>======代码======</script> -->
	</head>
	<body>
		<table cellspacing="1" id="myTable">
			<tr>
				<th width="200">
                  <input type="checkbox" id="selAll1" onchange="" />全选
				<input type="checkbox" id="selAll2" onchange="" />反选
                        </th>
				<th width="200">姓名</th>
				<th width="200">性别</th>
				<th width="200">专业</th>
				<th width="200">爱好</th>
			</tr>
			<tr>
				<td><input type="checkbox" id="b1" name="box" onchange="fu12()"/></td>
				<td>刘备</td>
				<td>男</td>
				<td>软件开发</td>
				<td>抽烟</td>
			</tr>
			<tr>
				<td><input type="checkbox" id="b2" name="box" onchange="fu12()"/></td>
				<td>关羽</td>
				<td>男</td>
				<td>国际贸易</td>
				<td>喝酒</td>
			</tr>
			<tr>
				<td><input type="checkbox" id="b3" name="box" onchange="fu12()"/></td>
				<td>张飞</td>
				<td>男</td>
				<td>园林设计</td>
				<td>烫头发</td>
			</tr>
			<tr>
				<td><input type="checkbox" id="b4" name="box" onchange="fu12()"/></td>
				<td>赵云</td>
				<td>男</td>
				<td>平面设计</td>
				<td>抽烟</td>
			</tr>
			<tr>
				<td><input type="checkbox" id="b5" name="box" onchange="fu12()"/></td>
				<td>黄忠</td>
				<td>男</td>
				<td>影视制作</td>
				<td>玩游戏</td>
			</tr>
			<tr>
				<td><input type="checkbox" id="b6" name="box" onchange="fu12()"/></td>
				<td>小乔</td>
				<td>女</td>
				<td>高级护理</td>
				<td>唱歌</td>
			</tr>
		</table>
		<script>
            
            //全选
            document.getElementById("selAll1").onclick = function () {
                var cbs = document.getElementsByName("box");
                var x=document.getElementById('selAll1')
                if (x.checked==true) {
                    for (var i = 0; i < cbs.length; i++) {
                            cbs[i].checked = true;
                    }
                }
                if(x.checked==false){
                    for (var i = 0; i < cbs.length; i++) {
                            cbs[i].checked = false;
                    }
                }
            }
           // 反选
            document.getElementById("selAll2").onclick = function () {
                var cbs = document.getElementsByName("box");
                for (var i = 0; i < cbs.length; i++) {
                    cbs[i].checked = !cbs[i].checked;
                }
            }
        
		</script>
	</body>
</html>